Copyright Blue Sky Studios.
This clip features effects in "Robots" for which little development was allocated. Much of what was accomplished here became seeds for further development. I find it necessary to hand-build and hand-keyframe an effect several times as proof-of-concept before building it procedurally. This is the method by which to become intimately familiar with its subtleties; much like painting a portrait familiarizes one better with the subject's likeness by forcing conscious examination of every subtle feature.
The pots were animated outside of the FX department. The suds surface is brute-force manual keyframing of control vertices on the patch. While it seems daunting, it is actually quite manageable with proper organization. Bubbles were created by Clay Budin.
The junk pile through which the saw blade crashes is the same technique - manual keyframing of CVs.
The oil spatter is composed of hand-keyframed spheres. FX was given an sketch of how the spatter should appear in the final frame. From that drawing I simply worked in reverse; essentially "outcome-based" animation.
The junk being dumped from the bucket is hand-keyframed. I emulated curling steam by emitting constantly from underlying hidden rotating geometry. It is an effective illusion (and very cheap).
Finally, the oil dripping onto Mr. Gunk's chest is hand-keyframed spheres, like the above oil spatter.